Microwave-induced dppm ligand substitution in triosmium clusters: Structural and DFT evaluation of Os3 clusters containing multiply activated dppm ligands through cyclometalation, ortho metalation, and P C bond cleavage

Reactions of diphosphine-stabilized Os3 clusters with triphenylantimony: syntheses and structures of new antimony-containing Os3 clusters via Sb-Ph bond cleavage

The reactivity of the trimetallic clusters [Os₃(CO)₁₀(μ-dppm)] [dppm = bis(diphenylphosphino)methane] and [HOs₃(CO)₈{μ₃-Ph₂PCH₂PPh(C₆H₄-μ₂,σ¹)}] with triphenylantimony (SbPh₃) has been examined. [Os₃(CO)₁₀(μ-dppm)] reacts with SbPh₃ in refluxing toluene to yield three new triosmium clusters [Os₃(CO)₉(SbPh₃)(μ-dppm)] (1), [HOs₃(CO)₇(SbPh₃){μ₃-Ph₂PCH₂PPh(C₆H₄-μ₂,σ¹)}] (2), and [HOs₃(CO)₇(SbPh₃)(μ-C₆H₄)(μ-SbPh₂)(μ-dppm)] (3). [HOs₃(CO)₈{μ₃-Ph₂PCH₂PPh(C₆H₄-μ₂,σ¹)}] reacts with SbPh₃ (excess) at room temperature to afford [Os₃(CO)₈(SbPh₃)(η¹-Ph)(μ-SbPh₂)(μ-dppm)] (4) as the sole product. A series of control experiments have also been conducted to establish the relationship between the different products. The molecular structure of each product has been determined by single-crystal X-ray diffraction analysis, and the bonding in these new clusters has been investigated by electronic structure calculations.